Claiming the crown for the world's most air-polluted city is Linfen, China. Located in the Shanxi province, Linfen sits in the heart of China's coal belt. The hills in the surrounding area are lined with mines, injecting burning coal, soot and toxic ash into the blue-black hazy air.

According to a Time article, hanging laundry in the city turns black before it dries completely. Dubbed "Hell on Earth" by a British journalist, spending a day in the city is equivalent to smoking three packs of cigarettes.

The nickel ore is smelted on site at Norilsk. The smelting is directly responsible for severe pollution, generally acid rain and smog. By some estimates, 1 percent of the entire global emissions of sulfur dioxide comes from this one city. Heavy metal pollution near Norilsk is so severe that it is now economically feasible to mine the soil, as a result of acquiring high concentrations of platinum and palladium through pollution.[7]

The Blacksmith Institute[3] included Norilsk in its 2007 list of the ten most polluted places on Earth. The list cites air pollution by particulates (including radioisotopes strontium-90, and caesium-137 and heavy metals nickel, copper, cobalt, lead and selenium) and by gases (such as nitrogen and carbon oxides, sulfur dioxide, phenols and hydrogen sulfide). The Institute estimates 4 million tons of cadmium, copper, lead, nickel, arsenic, selenium and zinc are released into the air every year.

surprised that hamilton harbour isn't there. it was #4 in the world for quite a while. not sure if it is being cleaned up, or if the other problem areas are just getting worse.

I don't know how it stands now, but i remember reading quite a bit about how much Hamilton harbour had been cleaned up. This is probably some 10 years ago or something. I gather it's nowhere near as bad now as it was in the 90s (which is the era i assume you are referring to).

I don't know how it stands now, but i remember reading quite a bit about how much Hamilton harbour had been cleaned up. This is probably some 10 years ago or something. I gather it's nowhere near as bad now as it was in the 90s (which is the era i assume you are referring to).

I remember driving by it for a couple of weeks in 2003 and noticing that it wasn't that bad. The steel factories closing/moving and tighter restrictions on air pollution probably had something to do with that.

I remember driving by it for a couple of weeks in 2003 and noticing that it wasn't that bad. The steel factories closing/moving and tighter restrictions on air pollution probably had something to do with that.

Going over the Skyway, it still smells like a fart launched by Godzilla after eating a giant, steel burrito.